#ifndef __M_FORMAT_HPP__
#define __M_FORMAT_HPP__

#include <iostream>
#include <memory>
#include <ctime>
#include <vector>
#include <cassert>
#include <sstream>
#include "util.hpp"
#include "level.hpp"
#include "message.hpp"

namespace mylog
{
    //抽象格式化子项基类
    class FormatItem
    {
    public:
        using ptr = std::shared_ptr<FormatItem>;
        virtual void format(std::ostream &out, LogMsg &msg) = 0;
    };
    //派生格式化子项子类
    class MsgFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out, LogMsg &msg) override
        {
            out << msg._payload;
        }
    };
    class LevelFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out, LogMsg &msg) override
        {
            out << LogLevel::toString(msg._level);
        }
    };
    class TimeFormatItem : public FormatItem
    {
    public:
        TimeFormatItem(const std::string &time_fmt = "%H:%M:%S")
            : _time_fmt(time_fmt)
        {}
        void format(std::ostream &out, LogMsg &msg) override
        {
            struct tm t;
            localtime_r(&msg._ctime, &t);
            char tmp[32] = {0};
            strftime(tmp, sizeof(tmp), _time_fmt.c_str(), &t);
            out << tmp;
        }
    private:
        std::string _time_fmt; // 时间格式
    };
    class FileFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out, LogMsg &msg) override
        {
            out << msg._file;
        }
    };
    class LineFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out, LogMsg &msg) override
        {
            out << msg._line;
        }
    };
    class ThreadFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out, LogMsg &msg) override
        {
            out << msg._tid;
        }
    };
    class LoggerFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out, LogMsg &msg) override
        {
            out << msg._logger;
        }
    };
    class TabFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out, LogMsg &msg) override
        {
            out << "\t";
        }
    };
    class NLineFormatItem : public FormatItem
    {
    public:
        void format(std::ostream &out, LogMsg &msg) override
        {
            out << "\n";
        }
    };
    class OtherFormatItem : public FormatItem
    {
    public:
        OtherFormatItem(const std::string &str)
            : _str(str)
        {}
        void format(std::ostream &out, LogMsg &msg) override
        {
            out << _str;
        }
    private:
        std::string _str;
    };

    class Formatter
    {
    public:
    /*
        %d 表示日期，包含子格式{%H:%M:%S}
        %t 表示线程ID
        %p 表示日志等级
        %c 表示日志器名称
        %f 表示文件名
        %l 表示行号
        %m 表示日志消息
        %n 表示换行符
        %T 表示制表符缩进
    */
        using ptr = std::shared_ptr<Formatter>;
        Formatter(const std::string &pattern = "[%d{%H:%M:%S}] [%t] [%p] [%c] [%f:%l]%T%m%n")
            :_pattern(pattern)
        {
            assert(parsePattern());
        }

        //格式化接口1
        std::string format(LogMsg &msg)
        {
            std::stringstream ss;
            for(auto &item : _items)
            {
                item->format(ss,msg);
            }
            return ss.str();
        }

        //格式化接口2
        void format(std::ostream &out, LogMsg &msg)
        {
            for(auto & item : _items)
            {
                item->format(out, msg);
            }
        }

    private:
        //对格式化规则字符串进行解析
        bool parsePattern()
        {
            //1、对格式化规则字符串进行解析
            std::vector<std::pair<std::string, std::string>> fmt_order;
            size_t pos = 0;

            std::string key, val;
            while(pos < _pattern.size())
            {
                //1、处理原始字符串
                if(_pattern[pos] != '%')
                {
                    val.push_back(_pattern[pos++]);
                    continue;
                }
                //2、是%，但是要判断是否是%% -> 原始字符%
                if(pos + 1 < _pattern.size() && _pattern[pos + 1] == '%')
                {
                    val.push_back('%');
                    pos += 2;
                    continue;
                }
                //3、走到这里就能说明是格式化字符
                if(val.empty() == false)
                {    
                    fmt_order.push_back(std::make_pair("", val));
                    val.clear();
                }

                //%后面是格式化字符
                pos++; //++之后指向%之后的格式化内容
                if(pos == _pattern.size())
                {
                    std::cout << "格式化字符%后面缺少内容!\n";
                    return false;
                }
                key = _pattern[pos];
                //判断格式化字符后面是否是{，如果是就要处理子规则
                pos++;
                if(pos < _pattern.size() &&_pattern[pos] == '{')
                {
                    pos++;
                    while(pos < _pattern.size() && _pattern[pos] != '}')
                    {
                        val.push_back(_pattern[pos++]);
                    }
                    if(pos == _pattern.size())
                    {
                        //没有}
                        std::cout << "子规则{}匹配错误!\n";
                        return false;
                    }
                    pos++;
                }
                fmt_order.push_back(std::make_pair(key, val));
                key.clear();
                val.clear();
            }

            //2、根据解析到的数据初始化格式化子项数组成员
            for(auto &item : fmt_order)
            {
                _items.push_back(createItem(item.first, item.second));
            }
            return true;
        }

        //根据不同的格式化字符创建不同的格式化子项对象
        FormatItem::ptr createItem(const std::string &key, const std::string &val)
        {
            if(key == "d")
                return std::make_shared<TimeFormatItem>(val);
            if(key == "t")
                return std::make_shared<ThreadFormatItem>();
            if(key == "p")
                return std::make_shared<LevelFormatItem>();
            if(key == "c")
                return std::make_shared<LoggerFormatItem>();
            if(key == "f")
                return std::make_shared<FileFormatItem>();
            if(key == "l")
                return std::make_shared<LineFormatItem>();
            if(key == "m")
                return std::make_shared<MsgFormatItem>();
            if(key == "n")
                return std::make_shared<NLineFormatItem>();
            if(key == "T")
                return std::make_shared<TabFormatItem>();
            if(key.empty())
                return std::make_shared<OtherFormatItem>(val);

            //没有匹配的格式化字符
            std::cout << "没有匹配的格式化字符: %" << key << "\n";
            abort();
            return FormatItem::ptr();
        }

    private:
        std::string _pattern; // 格式化字符串
        std::vector<FormatItem::ptr> _items; // 格式化子项列表
    };
}

#endif